2004 5.3L Silverado Losing Coolant

desrtrat · December 29, 2006

also get a block tester. will show any exaust gasses in the cooling system

oil loss/coolent loss.....i would start looking at a possable head gasket or cracked head.

and i know you did not want to hear that.....

good luck

99xjsport06 · January 10, 2007

also get a block tester. will show any exaust gasses in the cooling system

oil loss/coolent loss.....i would start looking at a possable head gasket or cracked head.

and i know you did not want to hear that.....

good luck

<{POST_SNAPBACK}>

But with a cracked head, or a blown/leaking head gasket, that should make the oil look like a chocolate milkshake, and it looks just fine and it showing no signs of mixing with coolant.

To update, the valve tapping has gone away for a bit (as far as I know...now that i'm back at school, there's no telling what it does during the week when i'm not home).

Coolant loss continues. But I just ran across another thread where somebody had the same problem on a 2004 Sierra with the 5.3, and it was the water pump gaskets. I'm definitely going to look into that this weekend....maybe see if I can't dig up a FSM, as I REALLY hate the Haynes and Chilton's manuals.

Oil smoke show has stopped, but it still uses oil....still not sure on that one.

Thanks all for the suggestions, and I welcome any more. I'll definitely keep yall updated.

I forgot to add that Oil pressure stays with in what appears to be a normal level based on a hot or a cold engine...IF ANYTHING maybe a tad on the high side when driven cold, but it may still be with in factory spec for this engine.....I have not looked up what the pressure is supposed to be.

99xjsport06 · January 23, 2007

Another update.

The tapping i'm almost certain now is NOT from the valves, but from a possible stuck lifter. It's not occurring almost every cold start up, and lasts for about 2-4 minutes on average. Slightly revving the engine seems to help get the lifter unstuck a bit faster, but I can't imagine that being good for the engine. I am currently running 10W30 Mobil 1 Synthetic and will probably change it to 5W30 of the same brand on the next change...which is in about 1000 miles. As a temp. solution to buy some more time, I'm considering adding some Lucas or other type of additive that is supposed to help with sticking lifters. Any thoughts on this?

Too bad the d**n thing has 90K on it, could have had this long taken care of had it still been under warranty.

I just saw the old thread on the PCV valve being a "remedy" for the blowing smoke, which I will certainly look into.

Coolant loss is still occurring, i'm going to look into replacing the WP gasket.

1999 Tahoe 4x4 · January 23, 2007

Sounds like you are about to completely ruin your engine. You got all the advice already on this thread yet it seems like you don't follow any of that. I'm sorry if I HAVE to sound like some smartass now.

Never the less, best of luck and I hope you find the problem.

99xjsport06 · January 24, 2007

Sounds like you are about to completely ruin your engine. You got all the advice already on this thread yet it seems like you don't follow any of that. I'm sorry if I HAVE to sound like some smartass now.

Never the less, best of luck and I hope you find the problem.

I'm doing the best that I can. I go to college full time during the week, and we are in the middle of moving for the 2nd time with another move coming once again in about a month, so time is something that we don't have much of, but like I said i'm doing the best that I can. The only time I am home is on the weekends. Plus I also have two Jeeps that need attention as well. I know i have my work cut out for me, trust me.

All I was doing was merely updating the thread, in case anybody else comes across similar issues in the future.

1999 Tahoe 4x4 · January 24, 2007

Sounds like you are about to completely ruin your engine. You got all the advice already on this thread yet it seems like you don't follow any of that. I'm sorry if I HAVE to sound like some smartass now.

Never the less, best of luck and I hope you find the problem.

I'm doing the best that I can. I go to college full time during the week, and we are in the middle of moving for the 2nd time with another move coming once again in about a month, so time is something that we don't have much of, but like I said i'm doing the best that I can. The only time I am home is on the weekends. Plus I also have two Jeeps that need attention as well. I know i have my work cut out for me, trust me.

All I was doing was merely updating the thread, in case anybody else comes across similar issues in the future.

OK, all understandable. You have to admit however that the answer is not to continiue to driving with the truck like this. Look, if your temperature is not stable (as you have described) and you are smelling coolant (as you have described) AND you are STILL DRIVING that truck, then you are sitting on a ticking time-bomb.

You might just have a small leak somewhere but can eventually end up burning your cylinder head. Indeed I think you already might have done that. Since you have mentioned that you are not the only driver. Of course I REALLY hope for you for no damage.

My best advice is NOT to drive the truck like that.

If you finally have time, get a leak tester (it's must tool for future use as well) and test the cooling sysytem as described before. Belive me you WILL find your leak this way. When you fix it, change the coolant as well and change your termostat (OEM GM) regardless if it was good or not. (It's less then $16)

Best of luck,

Andreas

I pressure test my cooling system al part of a routine inspection of the engine. Having done so I sleep much better

shortaz670 · January 24, 2007

Waterpump gasket are a very common problem on the 4.8 and 5.3, i have done a least a dozen gaskets, there are very cheap and easy to do, i would recommend to start there.

99xjsport06 · January 24, 2007

Sounds like you are about to completely ruin your engine. You got all the advice already on this thread yet it seems like you don't follow any of that. I'm sorry if I HAVE to sound like some smartass now.

Never the less, best of luck and I hope you find the problem.

I'm doing the best that I can. I go to college full time during the week, and we are in the middle of moving for the 2nd time with another move coming once again in about a month, so time is something that we don't have much of, but like I said i'm doing the best that I can. The only time I am home is on the weekends. Plus I also have two Jeeps that need attention as well. I know i have my work cut out for me, trust me.

All I was doing was merely updating the thread, in case anybody else comes across similar issues in the future.

OK, all understandable. You have to admit however that the answer is not to continiue to driving with the truck like this. Look, if your temperature is not stable (as you have described) and you are smelling coolant (as you have described) AND you are STILL DRIVING that truck, then you are sitting on a ticking time-bomb.

You might just have a small leak somewhere but can eventually end up burning your cylinder head. Indeed I think you already might have done that. Since you have mentioned that you are not the only driver. Of course I REALLY hope for you for no damage.

My best advice is NOT to drive the truck like that.

If you finally have time, get a leak tester (it's must tool for future use as well) and test the cooling sysytem as described before. Belive me you WILL find your leak this way. When you fix it, change the coolant as well and change your termostat (OEM GM) regardless if it was good or not. (It's less then $16)

Best of luck,

Andreas

I pressure test my cooling system al part of a routine inspection of the engine. Having done so I sleep much better

Thanks for the response Andreas. I couldn't agree more that parking the truck is the best thing to do, its just that sometimes it's not an option. I'm going to call some buddies of mine who owe me a favor and dont have their tools packed up in a pod right now and see if we can't tear into this thing in the next week or so. If not, we'll have to buck up and spend the $$$ on putting it in the shop. I'm about to lose my garage to work in for about 3 weeks untill we get into our new house. I absolutely hate having to take a vehicle to a shop, as my dad is a mechanic and i've grown up around engines and transmissions, and I much prefer to do the work myself. Granted this is my step dads truck, my dad is still willing to help out, so that I gain some more knowledge. It's just a matter of when he doesn't have something in his shop that he's working on.

For the cooling issue, if it's an internal leak, wouldn't that make the oil look milkshake like? Engine oil and transmission fluid both look normal, and do not smell of coolant, which is leading me to think external leak. However, given the amount that it's losing (about a gallon every 4 or so weeks), one would think you'd be able to see it leaking. I attempted to pressure test the system not too long ago, but the kit my dad has doesn't have a fitting big enough for the coolant bottle on this truck, so we weren't able to test it. I'm aware that this would definitely tell me where the leak is, just need to find a kit with a fitting big enough. Any recommendations as to a good kit?

For the lifter, do you think getting some marvel mystery oil or lucas or some other type of good additive, changing the oil to add the additive, running it a bit (per the instructions) and changing it again (once more, per the instructions) would be worth it? I'm thinking it might be too late at this point, but i'm open to anything that could possibly buy some more time, atleast untill we get into the house and dont have to worry about moving again.

Thanks again.

Tim

1999 Tahoe 4x4 · January 24, 2007

RE: For the cooling issue, if it's an internal leak, wouldn't that make the oil look milkshake like?

If you have just a SMALL leak definately not. You have to remember that the water will boil/steam out of the oil too. However using I gallon of coolant a month. That is a whole different story. Honestly I don't know if boiling out would be true for such large amounts too.

As far as for a leak tester kit, I guess the one from your local auto parts store has to work. (I have one form Snap-On: too expensive)

As far as the lifter I would say first things first. You have focus on your coolant leak first. I think the main thing is to find out if you have an internal leak due to cylinder head problems. "Desertrat" suggested to check for exhaust gases in the coolant. You also might send some of the oil out for analysis. There are some companies on the net that do that.

99xjsport06 · February 5, 2007

Just to update....

Changed the oil about two weeks ago. I added a pint of Marvel Mystery Oil in with the oil, and switched from 10W30 to 5W30, still Mobil 1 Synthetic. The lifter has not made any more noise since then. While I am aware there is still possibly a problem with the lifter, for now it looks as if we bought some time, until we are finally moved into the new house (in about 3 weeks or so).

The coolant issue is still there. I am going to pick up a leak tester kit sometime this week hopefully and see if I can't figure out where the hell it's going.

winston27502 · April 10, 2007

Just to update....

Changed the oil about two weeks ago. I added a pint of Marvel Mystery Oil in with the oil, and switched from 10W30 to 5W30, still Mobil 1 Synthetic. The lifter has not made any more noise since then. While I am aware there is still possibly a problem with the lifter, for now it looks as if we bought some time, until we are finally moved into the new house (in about 3 weeks or so).

The coolant issue is still there. I am going to pick up a leak tester kit sometime this week hopefully and see if I can't figure out where the hell it's going.

Any update - just joined this forum, have a 5.3Liter Suburban (177K miles) with very similar issues. Coincidently at last oil change, I switched to 10W30 in the hopes of stalling a dreaded rear main dripping. Have had the coolant loss and also a sound on cold start up like stuck valve - once it warms up sound goes away. Just interested if you found out any more before I take in to mechanic

Lindsey · April 12, 2007

hello is there any new info on this thread? My issue is similar but not consistent.

32rider · April 15, 2007

I just read the whole thread and in 99xjsport06 case I would have a pressure check done at a shop - find out where it is leaking and then replace the parts myself or with help from his Dad or friends. That way you don't waste time or money and you still get the satifaction and know how of doing it yourself.

Matt

99xjsport06 · May 2, 2007

Long over due update....

Nothing has changed in terms of coolant loss and oil loss, all is the same. I know it really should have been worked on by now, but we're just getting settled into our house and finding time to work on it (as well as finding all my tools...lol). The stuck lifter has come back with a vengeance, even with a pint of MMO mixed in. So it looks like valve stem seals and a set of lifters are in this thing's near future.

I am still not sold on the head gasket being bad, as I can still smell the coolant when I open the hood after driving it. So, with that said, in about a week and a half i'll be done with school and home for the summer. I will be putting a new water pump and a metal felpro gasket on, to try and stop the coolant loss, then move onto putting a set of lifters in to stop the knocking, and valve stem seals in to stop the oil burning.

The knocking is now for the most part to the point where if we need to go anywhere in it, we have to go out and start it up 5+ minutes before we want to leave and let the knocking run its course. I took a video of the knocking. However, it only knocked for about 10 seconds or so, and blew out minimal smoke (go figure).

Will update again in a week and a half or so when I have the new pump and gasket in.

Just wanted to do a quick update, for anybody else who comes upon this and would like to know of any updates, feel free to e-mail me at [email protected]. I don't check this forum very often (but will be doing more so now). If you need a quick response feel free to e-mail me.

99xjsport06 · May 13, 2007

Water pump and water pump gasket set went in yesterday. I was actually quite surprised at how easy it was to do. The only thing that made me ill was the lack of a drain on the Radiator, which meant I had to make a mess draining the coolant. I was also shocked at the price of what the water pump goes for, which retailed just over $200 (but with a nice little discount that I get I paid about $115 and some change).

I think I found the source of the leak as well. As I was unbolting the old water pump, when I got to the two bolts on the top right, I noticed they were dirty/oily, like they had been wet and dirt collected on them, where as the rest of the bolts were dry and clean. If this is the case, that would indicate which seals were leaking, and being on the top, would probably explain why I wasn't noticing any signs of coolant on the outside, but could still smell it after driving.

I'm keeping my fingers crossed that this is the case. If so, this will make putting in a new set of lifters and valve stem seals in the future, much easier. I'll update again in about a week as to if it looks like this was the solution to the coolant loss. If not, the head gasket is the only other option.